Recovery From Sudden Sensorineural Hearing Loss May Be Linked to Chronic Stress Levels and Steroid Treatment Resistance

Conditional Ablation of Glucocorticoid and Mineralocorticoid Receptors from Cochlear Supporting Cells Reveals Their Differential Roles for Hearing Sensitivity and Dynamics of Recovery from Noise-Induced Hearing Loss

Endogenous glucocorticoids (GC) are known to modulate basic elements of cochlear physiology. These include both noise-induced injury and circadian rhythms. While GC signaling in the cochlea can directly influence auditory transduction via actions on hair cells and spiral ganglion neurons, evidence also indicates that GC signaling exerts effects via tissue homeostatic processes that can include effects on cochlear immunomodulation. GCs act at both the glucocorticoid receptor (GR) and the mineralocorticoid receptor (MR). Most cell types in the cochlea express both receptors sensitive to GCs. The GR is associated with acquired sensorineural hearing loss (SNHL) through its effects on both gene expression and immunomodulatory programs. The MR has been associated with age-related hearing loss through dysfunction of ionic homeostatic balance. Cochlear supporting cells maintain local homeostatic requirements, are sensitive to perturbation, and participate in inflammatory signaling. Here, we have used conditional gene manipulation techniques to target Nr3c1 (GR) or Nr3c2 (MR) for tamoxifen-induced gene ablation in Sox9-expressing cochlear supporting cells of adult mice to investigate whether either of the receptors sensitive to GCs plays a role in protecting against (or exacerbating) noise-induced cochlear damage. We have selected mild intensity noise exposure to examine the role of these receptors related to more commonly experienced noise levels. Our results reveal distinct roles of these GC receptors for both basal auditory thresholds prior to noise exposure and during recovery from mild noise exposure. Prior to noise exposure, auditory brainstem responses (ABRs) were measured in mice carrying the floxed allele of interest and the Cre recombinase transgene, but not receiving tamoxifen injections (defined as control (no tamoxifen treatment), versus conditional knockout (cKO) mice, defined as mice having received tamoxifen injections. Results revealed hypersensitive thresholds to mid- to low-frequencies after tamoxifen-induced GR ablation from Sox9-expressing cochlear supporting cells compared to control (no tamoxifen) mice. GR ablation from Sox9-expressing cochlear supporting cells resulted in a permanent threshold shift in mid-basal cochlear frequency regions after mild noise exposure that produced only a temporary threshold shift in both control (no tamoxifen) f/fGR:Sox9iCre+ and heterozygous f/+GR:Sox9iCre+ tamoxifen-treated mice. A similar comparison of basal ABRs measured in control (no tamoxifen) and tamoxifen-treated, floxed MR mice prior to noise exposure indicated no difference in baseline thresholds. After mild noise exposure, MR ablation was initially associated with a complete threshold recovery at 22.6 kHz by 3 days post-noise. Threshold continued to shift to higher sensitivity over time such that by 30 days post-noise exposure the 22.6 kHz ABR threshold was 10 dB more sensitive than baseline. Further, MR ablation produced a temporary reduction in peak 1 neural amplitude one day post-noise. While supporting cell GR ablation trended towards reducing numbers of ribbon synapses, MR ablation reduced ribbon synapse counts but did not exacerbate noise-induced damage including synapse loss at the experimental endpoint. GR ablation from the targeted supporting cells increased the basal resting number of Iba1-positive (innate) immune cells (no noise exposure) and decreased the number of Iba1-positive cells seven days following noise exposure. MR ablation did not alter innate immune cell numbers at seven days post-noise exposure. Taken together, these findings support differential roles of cochlear supporting cell MR and GR expression at basal, resting conditions and especially during recovery from noise exposure.

Comparison of Intratympanic Steroid and Hyperbaric Oxygen Salvage Therapy Hearing Outcomes in Idiopathic Sudden Sensorineural Hearing Loss: A Retrospective Study

OBJECTIVES

Systemic steroids are the most common first-line therapy in sudden sensorineural hearing loss (SSNHL), with significant improvement in hearing outcomes in over 60% of patients. It is unknown why 40% of patients do not respond to systemic steroid therapy. Salvage treatment includes intratympanic steroids (ITS) and hyperbaric oxygenation (HBO) therapy, with inconsistent results reported. This study aimed to compare the results of ITS and HBO therapy in patients with SSNHL that previously failed systemic steroid therapy.

DESIGN

This is a comparative retrospective nonrandomized interventional cohort study, enrolling 126 patients with SSNHL. Out of these, 35 patients received HBO therapy, 43 patients received ITS, and 48 patients did not receive any second-line therapy (control group). Pure-tone audiograms were performed before and after the salvage therapy in the IT and HBO groups and at the same time interval in the control group. Study variables included age, time until therapy initiation, tinnitus status, and hearing outcomes, with a cutoff criteria of cumulative >30 dB improvement on all frequencies indicating recovery.

RESULTS

ITS and HBO therapy were associated with statistically significant hearing recovery at all frequencies compared to systemic steroids. The results show an average hearing improvement of 13.6 dB overall frequencies (250 to 8000 Hz) after ITS therapy and 7.4 dB in HBO therapy in comparison to the control group. Presence of significant hearing improvement positively correlated with age, ITS therapy, and HBO therapy. Presence of tinnitus before therapy was negatively correlated with hearing improvement. Patients with tinnitus present at the start of therapy improve 4.67 dB less on average compared to those without tinnitus. ITS therapy significantly reduced tinnitus compared to the other two treatment options. Patients with tinnitus present before therapy significantly improve hearing at low frequencies, compared to the control group.

CONCLUSIONS

ITS and HBO therapy show superior hearing results compared to observation alone after failed oral steroid therapy for SSNHL. ITS shows an additional positive impact on tinnitus reduction and shows superior hearing outcomes after salvage therapy.

Efficacy of Ginkgo biloba Extract Combined with Hormones in the Treatment of Sudden Deafness and Its Effect on the Reactivity of Peripheral Blood T Cell Subsets

This work was aimed at exploring the efficacy of Ginkgo biloba extract combined with hormones in the treatment of sudden deafness and the influence on the reactivity of peripheral blood T cell subsets (PBTCSs). In this work, 64 patients with sudden deafness who were treated in The First Affiliated Hospital of Hunan University of Traditional Chinese Medicine from August 2019 to August 2022 were selected as the research objects. The patients were randomly divided into a hormone group (treatment with prednisone acetate, n = 34) and a combination group (treatment with Ginkgo-Damole combined with prednisone acetate, n = 30). After the two groups of patients were treated in different ways, their efficacy, symptom improvement, changes in blood rheology, and PBTCSs were compared. The total effective rates (TERs) of the hormone group and the combination group were 76.32% and 95.73%, respectively (P < 0.05). The fibrinogen contents of the patients in the combination group were obviously lower than those in the hormone group after 5 d, 7 d, and 10 d of treatment (P < 0.05). The high blood viscosity (HBV) values of patients in the combination group at 5 d, 7 d, and 10 d after treatment were greatly lower than those in the hormone group (P < 0.05). The low blood viscosity (LBV) values after 3 d, 7 d, and 10 d of treatment in the combined group were much lower in contrast to those in the hormone group (P < 0.05). The CD3+, CD4+, and CD4+/CD8+ in peripheral blood in the combination group were sharply higher while the CD8+ in the combined group was lower in contrast to the hormone group (P < 0.05). There was no visible difference in the incidence of adverse reactions between the two groups of patients after treatment (P > 0.05). In conclusion, the combined application of Ginkgo biloba extract and hormones could effectively improve the abnormal hemorheological indexes of patients with sudden deafness and effectively relieve the imbalance of PBTCSs, which was safe.

Psychological state of patients with sudden deafness and the effect of psychological intervention on recovery

OBJECTIVE

To determine the effect of personalized psychological interventions on the recovery of patients with sudden deafness.

METHODS

Participants were 438 patients with sudden deafness who were randomly allocated to observation and control groups. Patients in the control group received routine nursing care and drug treatment. Patients in the observation group received personalized psychological interventions, routine nursing care and drug treatment. The Self-Rating Anxiety Scale (SAS) and the Self-Rating Depression Scale (SDS) were used to measure anxiety and depression. The Simple Coping Style Questionnaire (SCSQ) and the Satisfaction With Life Scale (SWLS) were used to evaluate coping styles, attitude toward life and quality of life.

RESULTS

Patients in both groups had similar SAS and SDS scores at the time of admission. After treatment, there was a significant difference in SAS and SDS scores between the observation and control groups, indicating that the observation group had less anxiety and depression. Both groups had increased SCSQ and SWLS scores following treatment, indicating improvements in positive coping and satisfaction with life.

CONCLUSION

Effective psychological interventions may change negative thoughts, increase response rate and improve quality of life.

[The efficacy of intratympanic or combined steroids as the salvage treatment for moderate-to-severe to profound sudden sensorineural hearing loss]

Objective:The objective is to investigate and compare the efficacy of intratympanic methylprednisolone or combination therapy as the salvage treatment for idiopathic sudden sensorineural hearing loss （ISSNHL）. Method:Ninety patients with moderate-to-severe to profound SSNHL which were unresponsive to the conventional treatment were recruited. Among these 90 patients, 45 patients underwent intratympanic methylprednisolone therapy （IMT） alone and 45 patients underwent systemic dexamethasone+IMT（systemic steroids+IMT）. IMT was performed every other day, with a total of four times. The pure-tone audiogram （PTA） before and after IMT or systemic steroids+IMT was conducted. And for those with tinnitus or anxiety, tinnitus handicap inventory（THI）, visual analog scale （VAS） as well as Hamilton anxiety rating scale （HAMA） were performed before and after the treatment. Result:The success rate was 31.1% with IMT and 51.1% with systemic steroids+IMT, and the difference was not significant between the two groups. The efficacy of patients with less than 30 days of onset was better than those with more than 30 days, and the difference was not significant, either. Both groups showed significant improvement in the scores of THI, VAS, and HAMA, but no significant difference was found between the two groups. Conclusion:Intratympanic methylprednisolone is recommended as the salvage treatment for patients with moderate-to-severe to profound SSNHL which showed little efficacy after the conventional treatment. Prompt medication improves the therapeutic efficacy.